Currently, a three-dimensional (3D) display technology has been a matter of great concern. In order to implement 3D display, a frequently-used 3D technology is to dispose a three-dimensional grating on a light emitting side of a display panel. The three-dimensional grating may be divided into an active grating and a passive grating, wherein, the active grating includes a liquid crystal slit grating, a liquid crystal lens grating and the like, and the passive grating includes a cylindrical lens grating and a slit grating, etc.
As shown in FIG. 1, it is illustrated with a case where a slit grating 101 is disposed on the light emitting side of the display panel as an example, light emitted from different sub-pixel units 102 (FIG. 1 is illustrated by taking 5 sub-pixel units as an example) in the display panel are projected into different viewing fields, and two eyes 103 of a viewer are respectively positioned within the different viewing fields, so a 3D sense can be produced. As shown in FIG. 1, a is a distance between the sub-pixel units 102 on the display panel and the slit grating 101, and b is a viewing distance of the 3D display device, i.e., a distance between the sub-pixel units 102 in the display panel and the eyes 103 of the viewer.
In a current 3D display technology, the distance a between the slit grating and the display panel is fixed, so the viewing distance b of the display panel viewed by the viewer is also fixed. When the viewer views the display panel at a distance other than the viewing range b, a problem of crosstalk may occur, affecting a 3D display effect.